Superior Keratoconus in Attention-Deficit Hyperactivity Disorder (ADHD): A Case Report and Literature Review

Abstract

Keratoconus is a progressive corneal ectasia that may lead to severe visual impairment. Superior keratoconus (SK) is an uncommon form of the disease, and few cases have been reported thus far. We present an unusual SK case and a literature review of this rare diagnosis. A 49-year-old man presented to the ophthalmology clinic complaining of decreased vision in his right eye. Previous medical and ocular histories included medically treated attention-deficit hyperactivity disorder (ADHD) and keratoconus, which were diagnosed only in adulthood. A dense posterior subcapsular cataract was observed in the right eye. Corneal tomography revealed bilateral asymmetric SK, which was more severe in the right eye. The patient demonstrated unique eye-rubbing habits, which helped him cope with his ADHD symptoms and correlated with the keratoconus severity in each eye. In a literature review, 11 previously published cases of SK were summarized, none of which were associated with ADHD or included ipsilateral cataracts as in our patient. In conclusion, ADHD may cause repetitive eye rubbing and subsequent uncommon corneal ectatic changes, such as SK. Early recognition and characterization of eye rubbing can be crucial in detecting coexisting mental and ocular disorders.